Knife for Surgical Stapler and Associated Method of Manufacture with MIM and HIP

ABSTRACT

A method is used to manufacture a knife of an end effector of a surgical instrument. The method includes forming the knife using metal injection molding. The knife has at least one feature having a molded shape. The method also includes machining the at least one feature of the knife to have a machined shape without machining the entire knife. The method also includes incorporating the knife into the end effector of the surgical instrument.

BACKGROUND

Endoscopic surgical instruments may include a shaft between the endeffector and a handle portion, which is manipulated by the clinician.Such a shaft may enable insertion through a trocar to a desired depthand rotation about the longitudinal axis of the shaft, therebyfacilitating positioning of the end effector within the patient.Positioning of an end effector may be further facilitated throughinclusion of one or more articulation joints or features, enabling theend effector to be selectively articulated or otherwise deflectedrelative to the longitudinal axis of the shaft.

Examples of endoscopic surgical instruments include surgical staplers.Some such staplers are operable to clamp down on layers of tissue, cutthrough the clamped layers of tissue, and drive staples through thelayers of tissue to substantially seal the severed layers of tissuetogether near the severed ends of the tissue layers. Merely exemplarysurgical staplers are disclosed in U.S. Pat. No. 7,380,696, entitled“Articulating Surgical Stapling Instrument Incorporating a Two-PieceE-Beam Firing Mechanism,” issued Jun. 3, 2008; U.S. Pat. No. 8,408,439,entitled “Surgical Stapling Instrument with An Articulatable EndEffector,” issued Apr. 2, 2013; and U.S. Pat. No. 8,453,914, entitled“Motor-Driven Surgical Cutting Instrument with Electric ActuatorDirectional Control Assembly,” issued Jun. 4, 2013. The disclosure ofeach of the above-cited U.S. patents and U.S. Patent Publications isincorporated by reference herein.

Surgical staplers may also be used in open procedures and/or othernon-endoscopic procedures. By way of example only, a surgical staplermay be inserted through a thoracotomy and thereby between a patient'sribs to reach one or more organs in a thoracic surgical procedure thatdoes not use a trocar as a conduit for the stapler. For instance, thevessels leading to an organ may be severed and closed by a staplerbefore removal of the organ from the thoracic cavity. Of course,surgical staplers may be used in various other settings and procedures.

While various kinds of surgical stapling instruments and associatedcomponents have been made and used, it is believed that no one prior tothe inventor(s) has made or used the invention described in the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention,and, together with the general description of the invention given above,and the detailed description of the embodiments given below, serve toexplain the principles of the present invention.

FIG. 1 depicts a perspective view of a first exemplary surgical staplinginstrument;

FIG. 2 depicts a side view of the instrument of FIG. 1 with a firstexemplary end effector;

FIG. 3 depicts a perspective view of the end effector of the instrumentof FIG. 1 in an open configuration;

FIG. 4A depicts a side cross-sectional view of the end effector of FIG.3, taken along line 4-4 of FIG. 3, with the firing beam in a proximalposition;

FIG. 4B depicts a side cross-sectional view of the end effector of FIG.3, taken along line 4-4 of FIG. 3, with the firing beam in a distalposition;

FIG. 5 depicts an end cross-sectional view of the end effector of FIG.3, taken along line 5-5 of FIG. 3;

FIG. 6 depicts an exploded perspective view of the end effector of FIG.3;

FIG. 7 depicts a perspective view of a second exemplary surgicalstapling instrument with a second exemplary end effector;

FIG. 8 depicts an enlarged side sectional view of the end effector ofFIG. 7;

FIG. 9 depicts a top front perspective view of a first exemplary knifeof the end effector of FIG. 7;

FIG. 10 depicts a bottom front perspective view of knife of FIG. 9;

FIG. 11 depicts a left side view of the knife of FIG. 9;

FIG. 12 depicts a right side view of the knife of FIG. 9;

FIG. 13 depicts a top front perspective view of a second exemplary knifethat may be incorporated into the end effector of FIG. 7;

FIG. 14A depicts an enlarged view of the anvil pin of the knife of FIG.13 prior to being machined;

FIG. 14B depicts an enlarged view of the anvil pin of the knife of FIG.13 after being machined;

FIG. 15 depicts a top front perspective view of a third exemplary knifethat may be incorporated into the end effector of FIG. 7; and

FIG. 16 depicts an exemplary method of manufacturing a knife that may beincorporated into the end effector of FIG. 7.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the invention may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presentinvention, and together with the description serve to explain theprinciples of the invention; it being understood, however, that thisinvention is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Thefollowing-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

For clarity of disclosure, the terms “proximal” and “distal” are definedherein relative to a human or robotic operator of the surgicalinstrument. The term “proximal” refers the position of an element closerto the human or robotic operator of the surgical instrument and furtheraway from the surgical end effector of the surgical instrument. The term“distal” refers to the position of an element closer to the surgical endeffector of the surgical instrument and further away from the human orrobotic operator of the surgical instrument. In addition, the terms“upper,” “lower,” “lateral,” “transverse,” “bottom,” “top,” are relativeterms to provide additional clarity to the figure descriptions providedbelow. The terms “upper,” “lower,” “lateral,” “transverse,” “bottom,”“top,” are thus not intended to unnecessarily limit the inventiondescribed herein.

In addition, the terms “first” and “second” are used herein todistinguish one or more portions of the surgical instrument. Forexample, a first assembly and a second assembly may be alternatively andrespectively described as a second assembly and a first assembly. Theterms “first” and “second” and other numerical designations are merelyexemplary of such terminology and are not intended to unnecessarilylimit the invention described herein.

I. FIRST EXEMPLARY SURGICAL INSTRUMENT HAVING A FIRST EXEMPLARY ENDEFFECTOR

FIGS. 1-6 depict a first exemplary surgical stapling and severinginstrument (10) that is sized for insertion through a trocar cannula oran incision (e.g., thoracotomy, etc.) to a surgical site in a patientfor performing a surgical procedure. Instrument (10) of the presentexample includes a handle portion (20) connected to a shaft (22), whichdistally terminates in an articulation joint (11), which is furthercoupled with a first exemplary end effector (12). Shaft (22) may beconstructed in accordance with at least some of the teachings of U.S.Pat. No. 9,795,379, entitled “Surgical Instrument with Multi-DiameterShaft,” issued Oct. 24, 2017, the disclosure of which is incorporated byreference herein.

Once articulation joint (11) and end effector (12) are inserted throughthe cannula passageway of a trocar, articulation joint (11) may beremotely articulated, as depicted in phantom in FIG. 1, by anarticulation control (13), such that end effector (12) may be deflectedfrom the longitudinal axis (LA) of shaft (22) at a desired angle (a).Articulation joint (11) and/or articulation control (13) may beconstructed and operable in accordance with at least some of theteachings of U.S. Pat. No. 9,186,142, entitled “Surgical Instrument EndEffector Articulation Drive with Pinion and Opposing Racks,” issued onNov. 17, 2015, the disclosure of which is incorporated by referenceherein; and/or U.S. Pat. No. 9,795,379, the disclosure of which isincorporated by reference herein.

End effector (12) of the present example includes a lower jaw (16) and apivotable anvil (18). Lower jaw (16) may be constructed in accordancewith at least some of the teachings of U.S. Pat. No. 9,808,248, entitled“Installation Features for Surgical Instrument End Effector Cartridge,”issued Nov. 7, 2017, the disclosure of which is incorporated byreference herein. Anvil (18) may be constructed in accordance with atleast some of the teachings of U.S. Pat. No. 9,517,065, entitled“Integrated Tissue Positioning and Jaw Alignment Features for SurgicalStapler,” issued Dec. 13, 2016, the disclosure of which is incorporatedby reference herein; U.S. Pat. No. 9,839,421, entitled “Jaw ClosureFeature for End Effector of Surgical Instrument,” issued Dec. 12, 2017,the disclosure of which is incorporated by reference herein; and/or U.S.Pub. No. 2014/0239037, entitled “Staple Forming Features for SurgicalStapling Instrument,” published on Aug. 28, 2014, the disclosure ofwhich is incorporated by reference herein.

Handle portion (20) includes a pistol grip (24) and a closure trigger(26). Closure trigger (26) is pivotable toward pistol grip (24) to causeclamping, or closing, of the anvil (18) toward lower jaw (16) of endeffector (12). Such closing of anvil (18) is provided through a closuretube (32) and a closure ring (33), which both longitudinally translaterelative to handle portion (20) in response to pivoting of closuretrigger (26) relative to pistol grip (24). Closure tube (32) extendsalong the length of shaft (22); and closure ring (33) is positioneddistal to articulation joint (11). Articulation joint (11) is operableto communicate/transmit longitudinal movement from closure tube (32) toclosure ring (33). Handle portion (20) also includes a firing trigger(28) (shown in FIG. 2). An elongate member (not shown) longitudinallyextends through shaft (22) and communicates a longitudinal firing motionfrom handle portion (20) to a firing beam (14) in response to actuationof firing trigger (28). This distal translation of firing beam (14)causes the stapling and severing of clamped tissue in end effector (12),as will be described in greater detail below.

FIGS. 3-6 depict end effector (12) employing an E-beam form of firingbeam (14). As best seen in FIGS. 4A-4B, firing beam (14) includes atransversely oriented upper pin (38), a firing beam cap (44), atransversely oriented middle pin (46), and a distally presented cuttingedge (48). Upper pin (38) is positioned and translatable within an anvilchannel (42) of anvil (18). Firing beam cap (44) slidably engages alower surface of lower jaw (16) by having firing beam (14) extendthrough lower jaw channel (45) (shown in FIG. 4B) that is formed throughlower jaw (16). Middle pin (46) slidingly engages a top surface of lowerjaw (16), cooperating with firing beam cap (44). Firing beam (14) and/orassociated lockout features may be constructed and operable inaccordance with at least some of the teachings of U.S. Pat. No.9,717,497, entitled “Lockout Feature for Movable Cutting Member ofSurgical Instrument,” issued Aug. 1, 2017, the disclosure of which isincorporated by reference herein.

FIG. 3 shows firing beam (14) of the present example proximallypositioned and anvil (18) pivoted to an open position, allowing anunspent staple cartridge (37) to be removably installed into a channelof lower jaw (16). As best seen in FIGS. 5-6, staple cartridge (37) ofthis example includes a cartridge body (70), which presents an upperdeck (72) and is coupled with a lower cartridge tray (74). As best seenin FIG. 3, a vertical slot (49) is formed through part of staplecartridge (37). As also best seen in FIG. 3, three rows of stapleapertures (51) are formed through upper deck (72) on one side ofvertical slot (49), with another set of three rows of staple apertures(51) being formed through upper deck (72) on the other side of verticalslot (49). As shown in FIGS. 4A-6, a wedge sled (41) and a plurality ofstaple drivers (43) are captured between cartridge body (70) and tray(74), with wedge sled (41) being located proximal to staple drivers(43). Wedge sled (41) is movable longitudinally within staple cartridge(37); while staple drivers (43) are movable vertically within staplecartridge (37). Staples (47) are also positioned within cartridge body(70), above corresponding staple drivers (43). Each staple (47) isdriven vertically within cartridge body (70) by a staple driver (43) todrive staple (47) out through an associated staple aperture (51). Asbest seen in FIGS. 4A-4B and 6, wedge sled (41) presents inclined camsurfaces that urge staple drivers (43) upwardly as wedge sled (41) isdriven distally through staple cartridge (37). Staple cartridge (37) maybe constructed and operable in accordance with at least some of theteachings of U.S. Pat. No. 9,517,065, the disclosure of which isincorporated by reference herein; and/or U.S. Pat. No. 9,808,248, thedisclosure of which is incorporated by reference herein.

With end effector (12) closed as depicted in FIGS. 4A-4B by distallyadvancing closure tube (32) and closure ring (33), firing beam (14) isthen advanced in engagement with anvil (18) by having upper pin (38)enter anvil channel (42). A pusher block (80) (shown in FIG. 5) islocated at the distal end of firing beam (14) and pushes wedge sled (41)as firing beam (14) is advanced distally through staple cartridge (37)when firing trigger (28) is actuated. During such firing, cutting edge(48) of firing beam (14) enters vertical slot (49) of staple cartridge(37), severing tissue clamped between staple cartridge (37) and anvil(18). As shown in FIGS. 4A-4B, middle pin (46) and pusher block (80)together actuate staple cartridge (37) by entering into vertical slot(49) within staple cartridge (37), driving wedge sled (41) into upwardcamming contact with staple drivers (43), which in turn drive staples(47) out through staple apertures (51) and into forming contact withstaple forming pockets (53) (shown in FIG. 3) on the inner surface ofanvil (18). FIG. 4B depicts firing beam (14) fully distally translatedafter completing severing and stapling of tissue. Staple forming pockets(53) are intentionally omitted from the view in FIGS. 4A-4B; but areshown in FIG. 3. Anvil (18) is intentionally omitted from the view inFIG. 5. In some versions, anvil (18) pivots about an axis that isdefined by a pin (or similar feature) that slides along an elongate slotor channel as anvil (18) moves toward lower jaw (16). In such versions,the pivot axis translates along the path defined by the slot or channelwhile anvil (18) simultaneously pivots about that axis.

Instrument (10) may otherwise be configured and operable in accordancewith any of the teachings of any of the patent references cited herein.Additional exemplary modifications that may be provided for instrument(10) will be described in greater detail below. The below teachings arenot limited to instrument (10) or devices taught in the patents citedherein. The below teachings may be readily applied to various otherkinds of instruments, including instruments that would not be classifiedas surgical staplers. Various other suitable devices and settings inwhich the below teachings may be applied will be apparent to those ofordinary skill in the art in view of the teachings herein.

II. EXEMPLARY KNIFES AND METHODS OF MANUFACTURE

A. Second Exemplary Instrument

FIG. 7 shows a perspective view of a second exemplary surgical staplinginstrument (110) with a second exemplary end effector (112) that isoperable to compress, staple, and cut tissue. Instrument (110) and endeffector (112) function similarly to instrument (10) and end effector(12) described above. As shown, instrument (110) includes a body (shownas a handle portion (120)), a shaft (122) extending distally from handleportion (120), with end effector (112) extending distally from shaft(122). Shaft (122) distally terminates in an articulation joint (111),which is coupled with end effector (112).

Similar to instrument (10), handle portion (120) includes a pistol grip(124) and a closure trigger (126). Closure trigger (126) is pivotabletoward pistol grip (124) to cause clamping, or closing, of anvil (118)toward lower jaw (116) of end effector (112). Such closing of anvil(118) is provided through a closure tube (132) and a closure ring (133),which both longitudinally translate relative to handle portion (120) inresponse to pivoting of closure trigger (126) relative to pistol grip(124). Closure tube (132) extends along the length of shaft (122).Closure ring (133) is positioned distal to articulation joint (111).Articulation joint (111) is operable to communicate/transmitlongitudinal movement from closure tube (132) to closure ring (133).Handle portion (120) also includes a firing trigger (128). An elongatemember (not shown) longitudinally extends through shaft (122) andcommunicates a longitudinal firing motion from handle portion (120) to afiring beam (114) in response to actuation of firing trigger (128). Thisdistal translation of firing beam (114) causes the stapling and severingof clamped tissue in end effector (112).

FIG. 8 shows an enlarged side sectional view of end effector (112) ofFIG. 7 with a first exemplary knife (210) as will be described ingreater detail below with reference to FIGS. 9-12. Lower jaw (116) isconfigured to receive staple cartridge (37). Lower jaw (116) includes alower jaw channel (145), similar to lower jaw channel (45), that isconfigured to receive a portion of knife (210). Likewise, anvil (118)includes an anvil channel (142) similar to anvil channel (42). As shownin FIG. 8, instead of using a single firing beam (14) as shown in FIG.6, firing beam (14) is separated into firing beam (114) and an exemplaryknife (210, 310, 410). Firing beam (114) and knife (210, 310, 410) maybe coupled together using a variety of different methods includingwelding and/or mechanical feature(s). As shown, a distal portion offiring beam (114) includes a coupling feature (146) that couples with aproximal coupling feature (212) of knife (210) as shown in greaterdetail in FIGS. 9-12.

In some conventional manufacturing processes, knife (210) of instrument(110) may be machined from a single solid block of material (e.g.metal). As a result, this machining of knife (210) may be time consumingand expensive, both of which are undesirable. As a result, it isdesirable to manufacture knife (210, 310, 410) using a faster, moreefficient, and more cost-effective process or system of processes.Conventional machining techniques, being reductive in nature, may alsobe considered as being inefficient since they may create waste in thematerial that is removed from the single solid block of material.Additionally, it may be desirable that specific portions and features ofknife (210, 310, 410) have tighter tolerances to enhance the performanceof instrument (110), while other specific portions and features of knife(210, 310, 410) may have looser tolerances where the precise dimensionsare of lesser significance. For example, tighter tolerances may bepreferred for surfaces that aid the distal movement of knife (210, 310,410) in end effector (112) of instrument (110). As such, it is desirableto manufacture knife (210, 310, 410) efficiently, cost effectively, androbustly. Although the present examples of instruments (10, 110) includesurgical staplers, it is contemplated that the teachings may be readilyapplied to knife members for various other kinds of instruments.

B. First Exemplary Knife

FIG. 9-12 show knife (210) as including a body (214) with distal andproximal ends (216, 218). Body (214) of knife (210) includes an anvilpin (220) disposed opposite a channel pin (222). Anvil pin (220)includes outwardly extending flanges (224 a-b). Flanges (224 a-b)respectively include upper surfaces (226) separated by upper surface(229), a lower surface (228), and lateral side surfaces (230 a-b)disposed therebetween. Flanges (224 a-b) are configured to interact withanvil channel (42, 142). Flanges (224 a-b) function similarly to upperpin (38) of firing beam (14). Like upper pin (38), flanges (224 a-b) arepositioned and translatable within anvil channel (42, 142) of anvil (18,118). Similar to anvil pin (220), channel pin (222) includes outwardlyextending flanges (232 a-b). Flanges (232 a-b) include upper surfaces(234 a-c), a lower surface (236), and lateral side surfaces (238 a-b)disposed therebetween. Flanges (232 a-b) function similarly to firingbeam cap (44) that slidably engages a lower surface of lower jaw (16) byhaving firing beam (14) extend through lower jaw channel (45) (shown inFIG. 4B) that is formed through lower jaw (16). Flanges (224 a-b, 232a-b) cooperate to maintain end effector (12, 112) in a closed stateduring actuation of the end effector (12, 112). As shown, upper surface(234 b) is recessed relative to upper surfaces (234 a, 234 c), resultingin a non-planar surface.

As shown in FIGS. 9-12, a cutting edge (240) is disposed adjacent distalend (216) of knife (210) and opposite coupling feature (212). Cuttingedge (240) is formed by the converging distal termination of opposingcutting surfaces (242). Knife (210) also includes a middle flange (244).Middle flange (244) functions similar to middle pins (46) whichslidingly engages a top surface of lower jaw (16), cooperating withfiring beam cap (44). Middle flange (244) includes outwardly extendingflanges (246 a-b) that are shown as being generally shaped as airfoils.Flanges (246 a-b) include an upper surface (248), a lower surface (250a-b), and lateral side surfaces (252 a-b) disposed therebetween.

As shown in FIGS. 9-12 using shading (hatching) of specific surfaces,certain feature(s) may be machined after being initially formed. Forexample, knife (210) may be initially formed using a near net metalinjection molding process. Metal injection molding (MIM) refers to anymetalworking process where finely-powdered metal is mixed with a bindermaterial to create a feedstock that is subsequently shaped andsolidified using molding process (such as injection molding). Metalinjection molding allows for high volume, complex parts to be shaped. Aswill be described in greater detail below, knife (210, 310, 410) andeach of its features have a molded shape, certain features of which aresubsequently machined to a machined shape. Machined features may have afiner surface finish than portions of knife (210, 310, 410) that havenot been machined.

Such feature(s) being machined after being formed may include one ormore of cutting edge (240), upper surface (229) of anvil pin (220),upper and lower surfaces (226, 228) of anvil pin (220), lower surface(250 a-b) of middle flange (244), and upper surface (234) of channel pin(222). Machining these features may provide many benefits. For example,upper and lower surfaces (226, 228) may be machined to improve thedimensional tolerances of the near net metal injection molding process.Improved dimensional tolerances of certain surfaces may improve thesliding interface between components moving relative to one another.Improving the sliding interface may reduce the wear associated withupper and lower surfaces (226, 228) of anvil pin (220) slidablyinteracting with anvil (18, 118). Similarly, upper surface (234 a-c) maybe machined to reduce the wear associated with slidably interacting withlower jaw channel (145) of lower jaw (116). Opposing cutting surfaces(242) may be machined after being formed using a near net metalinjection molding process to increase relative sharpness, which mayreduce a cutting force through the tissue. Machining opposing cuttingsurfaces (242) may specifically include grinding opposing cuttingsurfaces (242). It is also envisioned that other features includingother surfaces may also be machined.

C. Second Exemplary Knife

FIG. 13 shows a top front perspective view of a second exemplary knife(310) that may be used in end effector (112) in place of knife (210).Knife (310) includes a body (314) with distal and proximal ends (316,318). Body (314) includes an anvil pin (320) disposed opposite a channelpin (322). Anvil pin (320) includes outwardly extending flanges (324a-b). Flanges (324 a-b) include an upper surface (326), a lower surface(328), and lateral side surfaces (330 a-b) disposed therebetween.Flanges (324 a-b) function similarly to upper pin (38) of firing beam(14) and flanges (224 a-b) of knife (210). Like upper pin (38), flanges(324 a-b) are positioned and translatable within anvil channel (42, 142)of anvil (18, 118). Similarly, channel pin (322) includes outwardlyextending flanges (332 a-b). Flanges (332 a-b) include an upper surface(334), a lower surface (336), and lateral side surfaces (338 a-b)disposed therebetween. Flanges (332 a-b) function similarly to firingbeam cap (44) and flanges (232 a-b) of knife (210). Flanges (324 a-b,332 a-b) cooperate to maintain end effector (12, 112) in a closed stateduring actuation of end effector (12, 112).

Additionally, as shown in FIG. 13, a cutting edge (340) is disposedadjacent distal end (316) of knife (310) and opposite coupling feature(312). Cutting edge (340) is formed by the converging distal terminationof opposing cutting surfaces (342). Knife (310) also includes a middleflange (344). Middle flange (344) includes outwardly extending flanges(346), with outwardly extending flange (346 a) being shown and anotheroutwardly extending flange being hidden from view. Flange (346 a)includes an upper surface (348), a lower surface (350 a-b), and lateralside surface (352 a) disposed therebetween. Knife (310) also includesproximal aligning features (354), which are shown as tab shapedprojections in the present example. Proximal aligning features (354) maybe configured to engage firing beam (14, 114) of surgical instrument(10, 110). While seven proximal aligning features (354) are shown, moreor less aligning features of various shapes and sizes are alsoenvisioned. Additionally, the spacing between adjacent proximal aligningfeatures (354) may vary.

As shown in FIGS. 13-14B using shading (hatching) of specific surfaces,certain feature(s) may be machined after being formed. Such feature(s)may include one or more of opposing cutting surfaces (342) of cuttingedge (340), upper and lower surfaces (326, 328) of anvil pin (320),lower surface (350 a-b) of middle flange (344), and upper surface (334)of channel pin (322). For example, upper and lower surfaces (326, 328)may be machined to reduce wear while slidably interacting with anvil(18, 118). Similarly, upper surface (334) of channel pin (322) may bemachined to reduce the wear associated with slidably interacting withlower jaw channel (145) of lower jaw (116). Also, opposing cuttingsurfaces (342) may be machined (e.g. ground using a grinder) to increasethe sharpness of cutting surfaces (342) which reduces the cutting forcethrough the tissue. It is also envisioned that other features andsurfaces may also be machined.

FIG. 14A shows an enlarged view of anvil pin (320) of knife (310) ofFIG. 13 prior to machining but after being formed using a near net metalinjection molding process. FIG. 14B shows an enlarged view of anvil pin(320) of knife (310) after machining. As shown 14A, upper and lowersurfaces (326, 328) are machined to obtain the upper and lower surfaces(326, 328) in FIG. 14B. Machining removes material from the feature,such that the dimensions of the molded shape are greater than dimensionsof machined shape of the specific feature. For example, these reduceddimensions may be seen in FIGS. 14A-14B showing the molded andsubsequently machined upper and lower surfaces (326, 328) of anvil pin(320) of knife (310).

D. Third Exemplary Knife

FIG. 15 shows a top front perspective view of a third exemplary knife(410) that may be used in end effector (112) in place of knife (210,310). Knife (410) includes a body (414) with distal and proximal ends(416, 418). Body (414) includes an anvil pin (420) disposed opposite achannel pin (422). Anvil pin (420) includes outwardly extending flanges(424 a-b). Flanges (424 a-b) include an upper surface (426), a lowersurface (428), and lateral side surfaces (430 a-b) disposedtherebetween. Flanges (424 a-b) function similarly to upper pin (38) offiring beam (14) and flanges (224 a-b, 324 a-b) of knife (210, 310).Like upper pin (38), flanges (324 a-b) are positioned and translatablewithin anvil channel (42, 142) of anvil (18, 118). Similarly, channelpin (422) includes outwardly extending flanges (432 a-b). Flanges (432a-b) include an upper surface (434), a lower surface (436), and lateralside surfaces (438 a-b) disposed therebetween. Flanges (432 a-b)function similarly to firing beam cap (44) and flanges (232 a-b, 332a-b)) of knife (210, 310). Flanges (424 a-b, 432 a-b) cooperate tomaintain end effector (12, 112) in a closed state during actuation ofend effector (12, 112).

Additionally, as shown in FIG. 15, a cutting edge (440) is disposedadjacent distal end (416) of knife (410) and opposite coupling feature(412). Cutting edge (440) is formed by the converging distal terminationof opposing cutting surfaces (442). Knife (410) also includes a middlepin (444) adjacent proximal end (418) of knife (410). Middle pin (444)is functionally equivalent to middle pin (46). Similar to middle pin(46) that slidingly engages a top surface of lower jaw (16) cooperatingwith firing beam cap (44) described above with reference to FIGS. 1-6,middle pin (444) is configured to slidingly engage a top surface oflower jaw (16, 116), cooperating with flanges (424 a-b).

As shown in FIG. 15 with regard to knife (410), certain feature(s) maybe machined after being formed. Such feature(s) may include one or moreof opposing cutting surfaces (442) of cutting edge (440), lower surface(428) of anvil pin (420), and upper surface (434) of channel pin (422).For example, upper and lower surfaces (426, 428) may be machined toreduce the wear associated with slidably interacting with anvil (18,118). Similarly, upper surface (434) of channel pin (422) may bemachined to improve the respective tolerances which may reduce theassociated wear while slidably interacting with lower jaw channel (145)of lower jaw (116). Opposing cutting surfaces (442) may be machined toreduce a cutting force through the tissue. It is also envisioned thatother features and surfaces may also be machined.

E. Exemplary Method of Manufacturing

FIG. 16 shows an exemplary method (510) of manufacturing knife (210,310, 410) of end effector (12, 112) of surgical instrument (10, 110)that includes steps (512, 514, 516, 518). As shown, at step (512),method (510) includes forming knife (210, 310, 410) using metalinjection molding using a mold (520). Knife (210, 310, 410) and each ofits features have a molded shape. Instead of using metal injectionmolding, knife (210, 310, 410) may be formed using selective lasermelting, or direct metal laser sintering, or any other suitable additivemanufacturing process.

At step (514), method (510) includes hot isostatic pressing knife (210,310, 410) using a high-pressure vessel (522). Hot isostatic pressing(HIP) is a manufacturing process that is used to reduce the porosity ofmetals and increase the density of many ceramic materials. Hot isostaticpressing may result in one or more of densification of powderedcomponents, elimination of internal porosity, improvement of mechanicalproperties (such as increased resistance to fatigue and temperatureextremes, higher resistance to impact, wear and abrasion, and improvedductility), more efficient production (tighter tolerances, reduction inmachining, reduction in scrap). Hot isostatic pressing may be used onmetal components, ceramic components, and/or composite components. Forexample, knife (210, 310, 410) may be placed into high-pressure vessel(522) and subjected to high pressurized gases and/or high temperatures.While the hot isostatic pressing is shown in FIG. 16 as occurring at atime prior to machining, it is also envisioned that the hot isostaticpressing may occur at a time after machining. In other words, step (514)may occur before or after step (518). It is desirable to selectively usehot isostatic pressing on particular structural features of knife (210,310, 410).

At step (516), method (510) includes sintering knife (210, 310, 410)after hot isostatic pressing knife (210, 310, 410). Prior to sintering,knife (210, 310, 410) is considered to be in a “green state.” Sinteringmay be performed by inserting knife (210, 310, 410) into a furnace(524).

At step (518), method (510) includes machining feature(s) of knife (210,310, 410) to have a machined shape. It is desirable to machine onlyspecific feature(s) of knife (210, 310, 410) without machining theentire knife (210, 310, 410). The feature(s) may include a plurality ofdrive surfaces and cutting edge (240, 340, 440) of knife (210, 310,410). More specifically, the feature(s) may include cutting edge (240,340, 440), anvil pin (220, 320, 420), middle flange (244, 344), andchannel pin (222, 322, 422) of knife (210, 310, 410). More specifically,the surfaces of the feature(s) may include opposing cutting surfaces(242, 342, 442) of cutting edge (240, 340, 440), upper surface (229) ofanvil pin (220), upper surface (226, 326, 426) of channel pin (222, 322,422), lower surface (228, 328, 428) of anvil pin (220, 320, 420), andbottom surface (250 a-b, 350 a-b) of middle flange (244, 344). It may bedesirable to machine at least two of these surfaces, at least three ofthese surfaces, at least four of these surfaces, or at least each ofthese surfaces. If two or more features are imparted, the features maybe refined simultaneously or sequentially.

Machining removes material from the feature(s), such that the dimensionsof the molded or otherwise pre-machined shape are greater thandimensions of machined shape for the assessed feature. For example, thedimension reductions may be seen in comparing FIG. 14A showing themolded anvil pin (320) of knife (310) and FIG. 14B showing thesubsequently machined anvil pin (320). Machining specific features, andspecific surfaces of specific features, imparts tight tolerances whereexpressly desired. For example, tight tolerances may be preferred tominimize friction and associated wear of anvil pin (220, 320, 420) andchannel pin (222, 322, 422). Step (518) may be performed using a varietyof machining tools, for example, using a lathe (526), which may bemanually operated or automated. Machining is desired to broadlyencompass turning operation(s), milling operation(s), drillingoperations(s), and other miscellaneous machining operations. Forexample, machining may include grinding opposing cutting surfaces (242,342, 442) of cutting edge (240, 340, 440).

Machining specific features may identify material voids adjacent anouter surface of the feature that are present after hot isostaticpressing features of knife (210, 310, 410). Additionally, this secondaryclean-up machining allows for initial molded geometries having bettermold flow characteristics for the metal injection molding process. Thesemachining operations may leave indication marks on the connected sidewalls that show where machining was used and the amount of materialremoved. Metal injection molding knife (210, 310, 410), sintering, andsubsequently machining at least lower surface (228, 328, 428) of anvilpin (220, 320, 420) and upper surface (226, 326, 426) of channel pin(222, 322, 422), strengthens anvil pin (220, 320, 420) and channel pin(222, 322, 422). Improved anvil pin (220, 320, 420) and channel pin(222, 322, 422) characteristics reduce the requisite force to advanceknife (210, 310, 410) under loading. As such, using a near net metalinjection molding process and subsequent machining provides knife (210,310, 410) with higher performance machined features on the same distalcomponent. Additionally, method (510) provides a superior surface finishthan metal injection molding is capable of alone.

III. EXEMPLARY COMBINATIONS

The following examples relate to various non-exhaustive ways in whichthe teachings herein may be combined or applied. It should be understoodthat the following examples are not intended to restrict the coverage ofany claims that may be presented at any time in this application or insubsequent filings of this application. No disclaimer is intended. Thefollowing examples are being provided for nothing more than merelyillustrative purposes. It is contemplated that the various teachingsherein may be arranged and applied in numerous other ways. It is alsocontemplated that some variations may omit certain features referred toin the below examples. Therefore, none of the aspects or featuresreferred to below should be deemed critical unless otherwise explicitlyindicated as such at a later date by the inventors or by a successor-ininterest to the inventors. If any claims are presented in thisapplication or in subsequent filings related to this application thatinclude additional features beyond those referred to below, thoseadditional features shall not be presumed to have been added for anyreason relating to patentability.

Example 1

A method of manufacturing a knife of an end effector of a surgicalinstrument, the method comprising: (a) forming the knife using metalinjection molding, wherein the knife has at least one feature having amolded shape; (b) machining the at least one feature of the knife tohave a machined shape without machining the entire knife; and (c)incorporating the knife into the end effector of the surgicalinstrument.

Example 2

The method of Example 1, wherein the machining removes material from theat least one feature, such that the dimensions of the molded shape aregreater than the dimensions of the machined shape of the at least onefeature.

Example 3

The method of Examples 1 or 2, further comprising: hot isostaticpressing the knife before or after machining the at least one feature.

Example 4

The method of Example 3, wherein hot isostatic pressing occurs beforemachining the at least one feature.

Example 5

The method of Examples 3 or 4, further comprising: sintering the knifeafter hot isostatic pressing the knife and before machining the at leastone feature of the knife.

Example 6

The method of any one or more of Examples 1 through 5, wherein machiningthe at least one feature further comprises machining a plurality ofdrive surfaces and cutting surfaces of the knife.

Example 7

The method of any one or more of Examples 3 through 6, wherein machiningthe at least one feature identifies material voids adjacent an outersurface of the at least one feature present after the hot isostaticpressing of the knife.

Example 8

The method of any one or more of Examples 1 through 5, wherein machiningthe at least one feature further comprises machining at least a portionof each of a cutting edge, an anvil pin, a middle flange, and a channelpin of the knife.

Example 9

The method of any one or more of Examples 1 through 5, wherein machiningthe at least one feature further comprises machining at least each of acutting edge, a lower surface of an anvil pin, and an upper surface of achannel pin of the knife.

Example 10

The method of Example 9, wherein the upper surface of the channel pin isnon-planar.

Example 11

The method of any one or more of Examples 1 through 5, wherein machiningthe at least one feature further comprises machining upper and lowersurfaces of an anvil pin of the knife.

Example 12

The method of any one or more of Examples 1 through 5, wherein machiningthe at least one feature further comprises machining at least three of acutting edge, an upper surface of the anvil pin, a lower surface of theanvil pin, a lower surface of the middle flange, or an upper surface ofa channel pin of the knife.

Example 13

The method of any one or more of Examples 1 through 5, wherein machiningthe at least one feature further comprises machining at least each of acutting edge, an upper surface of the anvil pin, a lower surface of theanvil pin, a lower surface of the middle flange, and an upper surface ofa channel pin of the knife.

Example 14

The method of any one or more of Examples 1 through 13, whereinmachining the at least one feature produces a finer surface finish thana portion of the knife that has not been machined.

Example 15

The method of any one or more of Examples 1 through 14, wherein theknife further comprises a plurality of proximal aligning featuresconfigured to engage a firing rod of the surgical instrument.

Example 16

A method of manufacturing a knife of an end effector of a surgicalinstrument, the method comprising: (a) forming the knife using metalinjection molding, wherein the knife has at least one feature having amolded shape and a first surface finish; (b) hot isostatic pressing theknife; (c) machining the at least one feature of the knife to have amachined shape and a second surface finish without machining the entireknife, wherein the second surface finish is finer than the first surfacefinish; and (d) incorporating the knife into the end effector of thesurgical instrument.

Example 17

The method of Example 16, wherein machining the at least one featurefurther comprises machining at least each of a cutting edge, a lowersurface of an anvil pin, and an upper surface of a channel pin.

Example 18

The method of Example 16, wherein machining the at least one featureincludes grinding a cutting edge of the knife.

Example 19

An instrument, comprising: (a) a handle assembly; (b) a shaft extendingfrom the handle assembly; and (c) an end effector in communication withthe shaft, wherein the end effector is operable to compress, staple, andcut tissue, wherein the end effector comprises: (i) a first jawincluding a channel and configured to receive a staple cartridge, (ii) asecond jaw including an anvil, and (iii) a knife, wherein the knifecomprises: (A) a cutting edge including first and second opposing sides,wherein the first and second opposing sides are machined with aconfiguration to reduce a cutting force through the tissue, (B) an anvilpin including upper and lower surfaces, wherein at least the lowersurface is machined with a configuration to reduce wear associated withslidably interacting with the anvil, and (C) a channel pin that includesupper and lower surfaces, wherein at least the upper surface is machinedwith a configuration to reduce wear associated with slidably interactingwith the channel.

Example 20

The instrument of Example 19, wherein the knife further includes amiddle flange that includes upper and lower surfaces, wherein the lowersurface of the middle flange is machined, wherein both the upper andlower surfaces are machined to reduce the wear associated with slidablyinteracting with the channel.

Example 21

An instrument, comprising: (a) a handle assembly; (b) a shaft extendingfrom the handle assembly; and (c) an end effector in communication withthe shaft, wherein the end effector is operable to compress, staple, andcut tissue, wherein the end effector comprises: (i) a first jawincluding a channel and configured to receive a staple cartridge, (ii) asecond jaw including an anvil, and (iii) a knife, wherein the knifecomprises: (A) a body formed using metal injection molding and having afirst surface finish, (B) at least one feature formed in the body andhaving a molded shape, wherein the at least one feature of the knife issubsequently machined to have a machined shape with a second surfacefinish without machining the entire knife, wherein the second surfacefinish is finer than the first surface finish.

Example 22

The instrument of any one or more of Examples 19 through 21, wherein thedimensions of the molded shape are greater than the dimensions of themachined shape of the at least one feature.

Example 23

The instrument of any one or more of Examples 19 through 22, wherein theknife undergoes hot isostatic pressing before or after machining the atleast one feature.

Example 24

The instrument of Example 23, wherein the knife is sintered after hotisostatic pressing the knife and before the at least one feature of theknife is machined.

Example 25

The instrument of any one or more of Examples 21 through 24, wherein theat least one feature comprises a plurality of drive surfaces and cuttingsurfaces of the knife.

Example 26

The instrument of any one or more of Examples 21 through 25, wherein theat least one feature is machined to identify material voids adjacent anouter surface of the at least one feature present after hot isostaticpressing the knife.

Example 27

The instrument of any one or more of Examples 19 through 26, wherein theat least one feature further comprises at least a portion of each of acutting edge, an anvil pin, a middle flange, and a channel pin of theknife.

Example 28

The instrument of any one or more of Examples 21 through 24, wherein theat least one feature further comprises at least each of a cutting edge,a lower surface of an anvil pin, and an upper surface of a channel pinof the knife.

Example 29

The instrument of any one or more of Examples 21 through 26, wherein theat least one feature further comprises upper and lower surfaces of ananvil pin of the knife.

Example 30

The instrument of any one or more of Examples 21 through 24, wherein theat least one feature further comprises at least three of a cutting edge,an upper surface of the anvil pin, a lower surface of the anvil pin, alower surface of the middle flange, or an upper surface of a channel pinof the knife.

Example 32

The instrument of any one or more of Examples 21 through 24, wherein theat least one feature further comprises at least each of a cutting edge,an upper surface of the anvil pin, a lower surface of the anvil pin, alower surface of the middle flange, and an upper surface of a channelpin of the knife.

Example 33

The instrument of any one or more of Examples 21 through 32, wherein theat least one feature has a finer surface texture after being machinedthan a portion of the knife that has not been machined.

Example 34

The instrument of any one or more of Examples 19 through 33, wherein theknife further comprises a plurality of proximal aligning featuresconfigured to engage a firing rod of the surgical instrument.

IV. MISCELLANEOUS

It should be understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Theabove-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions of the devices described above may have application inconventional medical treatments and procedures conducted by a medicalprofessional, as well as application in robotic-assisted medicaltreatments and procedures. By way of example only, various teachingsherein may be readily incorporated into a robotic surgical system suchas the DAVINCI™ system by Intuitive Surgical, Inc. of Sunnyvale, Calif.

Versions of the devices described above may be designed to be disposedof after a single use, or they can be designed to be used multipletimes. Versions may, in either or both cases, be reconditioned for reuseafter at least one use. Reconditioning may include any combination ofthe steps of disassembly of the device, followed by cleaning orreplacement of particular pieces, and subsequent reassembly. Inparticular, some versions of the device may be disassembled, and anynumber of the particular pieces or parts of the device may beselectively replaced or removed in any combination. Upon cleaning and/orreplacement of particular parts, some versions of the device may bereassembled for subsequent use either at a reconditioning facility or bya user immediately prior to a procedure. Those skilled in the art willappreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

I/We claim:
 1. A method of manufacturing a knife of an end effector of asurgical instrument, the method comprising: (a) forming the knife usingmetal injection molding, wherein the knife has at least one featurehaving a molded shape; (b) machining the at least one feature of theknife to have a machined shape without machining the entire knife; and(c) incorporating the knife into the end effector of the surgicalinstrument.
 2. The method of claim 1, wherein the machining removesmaterial from the at least one feature, such that the dimensions of themolded shape are greater than the dimensions of the machined shape ofthe at least one feature.
 3. The method of claim 1, further comprising:hot isostatic pressing the knife before or after machining the at leastone feature.
 4. The method of claim 3, wherein hot isostatic pressingoccurs before machining the at least one feature.
 5. The method of claim3, further comprising: sintering the knife after hot isostatic pressingthe knife and before machining the at least one feature of the knife. 6.The method of claim 3, wherein machining the at least one featurefurther comprises machining a plurality of drive surfaces and cuttingsurfaces of the knife.
 7. The method of claim 3, wherein machining theat least one feature identifies material voids adjacent an outer surfaceof the at least one feature present after the hot isostatic pressing ofthe knife.
 8. The method of claim 3, wherein machining the at least onefeature further comprises machining at least a portion of each of acutting edge, an anvil pin, a middle flange, and a channel pin of theknife.
 9. The method of claim 1, wherein machining the at least onefeature further comprises machining at least each of a cutting edge, alower surface of an anvil pin, and an upper surface of a channel pin ofthe knife.
 10. The method of claim 1, wherein the upper surface of thechannel pin is non-planar.
 11. The method of claim 1, wherein machiningthe at least one feature further comprises machining upper and lowersurfaces of an anvil pin of the knife.
 12. The method of claim 1,wherein machining the at least one feature further comprises machiningat least three of a cutting edge, an upper surface of the anvil pin, alower surface of the anvil pin, a lower surface of the middle flange, oran upper surface of a channel pin of the knife.
 13. The method of claim1, wherein machining the at least one feature further comprisesmachining at least each of a cutting edge, an upper surface of the anvilpin, a lower surface of the anvil pin, a lower surface of the middleflange, and an upper surface of a channel pin of the knife.
 14. Themethod of claim 1, wherein machining the at least one feature produces afiner surface texture than a portion of the knife that has not beenmachined.
 15. The method of claim 1, wherein the knife further comprisesa plurality of proximal aligning features configured to engage a firingrod of the surgical instrument.
 16. A method of manufacturing a knife ofan end effector of a surgical instrument, the method comprising: (a)forming the knife using metal injection molding, wherein the knife hasat least one feature having a molded shape and a first surface finish;(b) hot isostatic pressing the knife; (c) machining the at least onefeature of the knife to have a machined shape and a second surfacefinish without machining the entire knife, wherein the second surfacefinish is finer than the first surface finish; and (d) incorporating theknife into the end effector of the surgical instrument.
 17. The methodof claim 16, wherein machining the at least one feature furthercomprises machining at least each of a cutting edge, a lower surface ofan anvil pin, and an upper surface of a channel pin.
 18. The method ofclaim 16, wherein machining the at least one feature includes grinding acutting edge of the knife.
 19. An instrument, comprising: (a) a handleassembly; (b) a shaft extending from the handle assembly; and (c) an endeffector in communication with the shaft, wherein the end effector isoperable to compress, staple, and cut tissue, wherein the end effectorcomprises: (i) a first jaw including a channel and configured to receivea staple cartridge, (ii) a second jaw including an anvil, and (iii) aknife, wherein the knife comprises: (A) a cutting edge including firstand second opposing sides, wherein the first and second opposing sidesare machined with a configuration to reduce a cutting force through thetissue, (B) an anvil pin including upper and lower surfaces, wherein atleast the lower surface is machined with a configuration to reduce wearassociated with slidably interacting with the anvil, and (C) a channelpin that includes upper and lower surfaces, wherein at least the uppersurface is machined with a configuration to reduce wear associated withslidably interacting with the channel.
 20. The instrument of claim 19,wherein the knife further includes a middle flange that includes upperand lower surfaces, wherein the lower surface of the middle flange ismachined, wherein both the upper and lower surfaces are machined toreduce the wear associated with slidably interacting with the channel.